- Phase I: Patients undergo external beam radiotherapy to the pelvis and para-aortic region 5 days a week for 5 weeks. Patients also undergo either intracavitary low-dose rate (LDR) brachytherapy in 2 applications beginning within 2 weeks after completion of external beam radiotherapy at 2-3 week intervals or 6 fractions of high-dose rate intracavitary brachytherapy over 8 weeks beginning as early as week 2 of external beam radiotherapy. Patients also receive cisplatin IV over 1 hour weekly for 6 weeks concurrently with external beam radiotherapy and once with LDR brachytherapy. Phase II proceeds only if toxicity in phase I is within expected parameters.